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1" PE design question

Hi everyone,

I read somewhere that I should use 3/4" PE running to the last head in a zone. My plan calls for 1" all around.

Unless I change something, I need 528 feet of PE. I can only get PE in 100 ft length. So, can I use 28 ft of my leftover 3/4" PE on my last head that will be MP Rotator MP1000. Last 28 feet runs downhill about 5 feet elevation drop.

There is no practical modern need to reduce pipe size. The practice made sense in olden days, with older sprinkler heads, and no swing pipe connections. The idea then was a smaller pipe at the end of the run would be a "brake" to the onrush of water that could cause damage at the moment the air left the last sprinkler, and the water would hit it like a battering ram.

Golf course systems can have worries about the "battering ram" effect, but they are dealing with water on a much larger scale. They can use specialty control valves that open only partially, until the point is reached where all the air has left a zone. Home systems in days of old had heads with higher flow rates than modern sprinklers, so they had more worries.